ping
NetworkPackage: iputils-ping
Sends ICMP packets and times the reply. It proves a machine is reachable at the IP level; it says nothing about port 443, and a firewall dropping ICMP makes it fail on a perfectly healthy server.
What its options do in the lessons
From the same glossary the lessons render under their commands, so the two cannot disagree.
ping -c- Stops after sending that many packets, instead of running until Ctrl+C.